1. Field of the Invention
The present invention relates to a lens-shaped article or the like and a method and apparatus for the manufacture of the same.
2. Description of the Prior Art
It is difficult to support a crystal resonator having its both surfaces machined into lens-shaped configurations. In the past there has been employed a method of supporting the crystal resonator at several points on its circumference by means of a mica plate or the like having a V-shaped cross section. In this case, since mismatching of vibration naturally occurs between the resonator and the support system, even if the resonator is made as small as possible and with a high quality factor Q, there are possibilities that the mismatching impairs the Q and yields sub-vibration.
The crystal resonator must be formed at a certain angle bearing an important relation to the crystal axis of a work but, with the prior art, only one surface of the work can be machined so as to retain the axis.